Navigational device

ABSTRACT

A navigational device for guiding a vehicle within a network of traffic routes provides, for guidance purposes, a guide object that is shown in relation to the traffic route in such a manner that the guide object&#39;s movement represents driving maneuvers to be performed by the driver. The driver emulates the driving maneuvers shown to him/her and thus follows the previously calculated route.

FIELD OF THE INVENTION

The present invention is related to a navigational device for guiding avehicle.

BACKGROUND INFORMATION

Navigational devices for guiding a vehicle within a network of trafficroutes provide that driving instructions are optically displayed by adisplay of arrow representations in a display in front of the driver.Such an optical display may be augmented by an acoustic output in that adescription of the driving instruction, for example “turn right now” isoutput along with the display. The driver, acting on his/her own,associates the driving instructions with the prevailing trafficsituation up ahead. The driver is shown a three-dimensional view of theroads up ahead to provide him/her with a most realistic as possiblerepresentation of these roads.

SUMMARY

The navigational device according to the present invention provides thata guide object is shown to the driver, and he/she merely needs to followthe guide object. For this purpose, the guide object is shown virtuallyon a suitable display, e.g., traveling a short way in front of thedriver, along the travel route to be traveled by the driver. The guideobject demonstrates to the driver the driving maneuvers that he/sheshould execute, so that the driver merely needs to follow along andemulate the appropriate driving maneuvers.

Thus, the need for converting symbolic, optical displays or acousticinstructions into an active driving maneuver, is eliminated. Byemulating the action demonstrated by the guide object, it is possible toeliminate linguistic misunderstandings, such as mixing up the left andright sides, when responding to a driving instruction. Also, vehicleguidance is made easier for inexperienced drivers.

As a guide object, an image of a vehicle may be used, since this may beeasily recognized by a driver and reminds the driver of a situationwhere the driver, in accordance with a previous arrangement, follows areal vehicle driving ahead, to a previously agreed upon destination.

In addition, the guide object may be placed at a given distance in frontof a current position of the vehicle on the travel route and to indicatethe same, since, in this manner, the driver is given enough time toreproduce the driving maneuver executed by the guide object. Thisdistance is may be selected as a function of the current vehiclevelocity, the distance being increased with increasing vehicle velocityto provide the driver with enough time to react to the driving maneuverthat is displayed.

In addition, the guide object may be overlaid directly into the driver'sfield of view on the traffic route arranged in front of him/her. In thismanner, there is no need for the driver to turn his/her eyes away fromthe travel path, and he/she is nevertheless guided by the guide objectin accordance with the travel route planned by the driver.

In the case of a representation in a display outside of the field ofview, it may be advantageous to also show the area surrounding thetraffic route, for example buildings surrounding the traffic route, tomake it easier for the driver to orient himself/herself and to correlatethe guide object to the actual road conditions.

An arrangement for sensing a traffic situation is provided, for examplea sensor system to sense the distance to other vehicles arranged in thevicinity of the vehicle, e.g., to the side of the vehicle and in frontof the vehicle. In this manner, a display of the guide object may becontrolled if there is an obstacle arranged in front of the vehicle or avehicle traveling in front of the vehicle in such a manner that theguide object is suitably delayed and made to virtually approach theobstacle at an adapted velocity. The driver, using his/her control,e.g., the brake, may then react already to this warning display of theguide object and adapt his/her velocity accordingly. In addition, anarrangement for determining the actual highest permissible speed may beprovided to ensure that the guide object does not move more rapidlyalong the travel route than may be allowed by the highest permissiblespeed at this location, the current position being determined for thispurpose, for example, by a position-finding system. In this manner, thedriver, who is following the guide object, is deterred from exceeding ahighest permissible, currently effective speed in each instance.

To aid the driver, other display fields are may be provided to warnhim/her of other dangers or to display traffic signs sensed by anoptical unit. Display areas are provided on the guide object in order todisplay warning information, for example in written form, or adirectional indication on the guide object. In this connection, forexample, a directional signal may be shown or, as warning information, adisplay of a brake light activation.

To augment the optical display, an acoustic output may be provided inorder to warn the driver in a more comprehensive manner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic configuration of a navigational deviceaccording to the present invention.

FIG. 2 shows a first example embodiment of a display of a navigationaldevice according to the present invention.

FIG. 3 shows a second exemplary embodiment of a display of anavigational device according to the present invention.

FIG. 4 shows a functional sequence of a turning operation, utilizing aguidance by the navigational device according to the present invention.

FIG. 5 shows an example of a passing operation, utilizing a guidance bythe navigational device according to the present invention.

DETAILED DESCRIPTION

The navigational device according to the present invention may be usedfor guiding any vehicles at all within a network of traffic routes. Itsuse for guiding a motor vehicle in a road network may be advantageous,since this entails driving maneuvers which, to some degree, arecomplicated and are performed out over short distances, especially in aninner-city area. The navigational device according to the presentinvention is elucidated in the following on the basis of an example of anavigational device that is installed in a motor vehicle.

FIG. 1 illustrates a navigational device 1 including a centralprocessing unit 2 to which a display 3 is connected. Central processingunit 2 includes a processing unit 4. Also connected to centralprocessing unit 2 is a position-finding device 5 for determining themomentary vehicle position. Position-finding device 5 is may beconfigured as a satellite-based position-finding unit for determiningpositions via a satellite-based position-finding system, e.g., the GPS(global positioning system). In addition, rate-of-rotation and distancesensors may be connected to central processing unit 2 to determinepositions. Moreover, any other vehicle position-finding systems fordetermining positions may also be used. Processing unit 4 may access adata storage-medium drive 6 including a data storage medium including aroad network stored thereon. The navigational device is controllable viaa control unit 7 by actuating selection keys 8. Also linked to centralprocessing unit 2 are a loudspeaker 9 for acoustic output, a cameradevice 10 for observing the driving area arranged in front of thevehicle, and distance sensors 11 for determining the distance tovehicles traveling ahead of or next to the vehicle. Distance sensors 11may be configured as radar sensors, as ultrasonic sensors and/or asvideo sensors. A current position of the vehicle is determined usingposition-finding device 5. Via selection keys 8 of control unit 7, atthis point, a user enters a destination into navigational device 1,processing unit 4 determining a travel route from the current vehicleposition to the indicated destination by accessing the data storagemedium, in the form of a CD Rom, for example, inserted in datastorage-medium drive 6. Appropriate driving instructions are output viadisplay 3, as well as over loudspeaker 9, to the driver, to implementthe driving action, as soon as a designated position for outputting thedriving instruction has been reached via position-finding device 5. Inone exemplary embodiment, central processing unit 2, as well as datastorage-medium drive 6 and control unit 7 are configured in a centerconsole of the vehicle.

FIG. 2 shows a first exemplary embodiment of a display of a guide objectin accordance with the present invention. In this exemplary embodiment,display 3 is configured as a so-called head-up display, where, as aguide object, a vehicle image 20 is projected, e.g., as a virtual image,onto a windshield 21 in front of the driver. In this context, the driverperceives vehicle image 20 as being superimposed on actual travel path(road) 23, i.e., the road ahead of him/her. In the process, vehicleimage 20 is made visible on windshield 21 in such a manner that itsappearance is analogous to an actual vehicle traveling in front of thedriver. Thus, vehicle image 20 may be made visible in travel path 23 ata distance that corresponds to the so-called half speedometer distance,thus it is approximately distant by half of the amount of the currentvehicle speed in kilometers per hour. Vehicle image 20, which,accordingly, is made visible in the travel path, to the right of a lanemarking 24, is displayed along a travel route 25 drawn in with dottedlines that had previously been calculated by processing unit 4. In afirst exemplary embodiment, the travel route itself is not shown.However, in another exemplary embodiment, it is also possible to overlaya course of the travel route onto the travel path. In this context, therepresentation in a virtual display enables vehicle image 20 to be shownin such a manner that a spatial impression is created for an observer,so that the virtual image actually appears to be distant from thevehicle by a distance that corresponds to its size. This entailsadapting the size of the vehicle image to the calculated distance. Thus,the smaller the distance of the vehicle to the virtual position ofvehicle image 20, the larger vehicle image 20 appears to the driver. Inthe present exemplary embodiment, a right turn is planned in travelroute 25 at the next exit from road 23, i.e., the previous travel path,into a side road 26. To this end, a right turn-signal display field 27is activated in vehicle image 20, directing the driver to actuate thedirectional signal of his/her vehicle, to the extent possible, in timebefore reaching the intersection. After turning off, right turn-signaldisplay field 27 extinguishes again. Vehicle image 20 may also includebrake-light fields 28, as well as a left turn-signal display field 29.The purpose of the left turn-signal field is to indicate a left-turnoperation; brake-light fields 28 indicate a deceleration to beundertaken. Thus, they may be activated, for example, shortly before theturn-off into side road 26 and thereby inform the driver of the need todecelerate his/her vehicle. In addition thereto, other guide symbols,such as a turn-off arrow 30 or a speed indication 31 may be made visiblein windshield 21 as well, to provide the driver with additionalinformation for his/her trip. In this context, the additionalinformation 30, 31 may be placed at the edge of the windshield, so asnot to hinder the driver's field of view to the extent that is possible.For this reason, the vehicle image display may be configured in such amanner that merely regions of the windshield are colored, so thatprocesses taking place beyond the vehicle image are still easilyvisible. This may also be accomplished, for example, by reducing thedisplay to an outline representation including the corresponding warningfields, so that the driver's field of view is not interfered with.

Instead of a vehicle image, other objects may be made visible as well.These may be, for example, simple graphic objects, for example a circleor, in some instances, also an object formed by dots, which retains itssize, independently of a virtual distance. In this manner, the outlayfor a calculation is reduced, as compared to a representation of avehicle image, for example. In some instances, these objects may alsoinclude display areas for a directional display and/or a warningdisplay.

Vehicles in the area surrounding the vehicle are able to be ascertainedusing camera device 10 and/or distance sensors 11. Under conditions ofvery heavy traffic directly in front of the vehicle, overlaying anadditional vehicle could distract the driver from these vehicles. Forthat reason, another exemplary embodiment of the present inventionprovides for suppressing the insertion of a guide object when thedistance to a vehicle driving in front of the vehicle falls below acertain magnitude, such as 50 meters. In such a case, drivinginstructions are output acoustically via loudspeaker 9.

In another exemplary embodiment, distance sensors 11 and/or cameradevice 10 are used to determine the distance to other vehicles drivingahead of the vehicle, the velocity of the guide object being adapted tothe velocity of these other vehicles traveling in front of the vehicle.Thus, a driver is able to control the velocity of his/her vehicle inaccordance with the traffic up ahead.

In addition, traffic signs may be recognized, for example, via cameradevice 10 and, in accordance with symbolically shown speed indication31, being displayed as well in windshield 21. In this context, thecurrent highest velocity is included in the consideration whencalculating the velocity of the virtual motion of the guide object. Inaddition, via an air interface 12, current highest velocities may eitherbe transmitted from a service control point or from transmittinginstallations located along the side of the road, to central processingunit 2, in the same manner as the highest velocities recorded by cameradevice 10, these being included in the consideration when displaying theguide object.

Another exemplary embodiment of display 3 is illustrated in FIG. 3. In adisplay area 40, which is arranged in front of the driver, either in anindicating instrument behind the steering wheel or in the centerconsole, a course of a road 41 is shown directly in front of thevehicle. In this connection, in one exemplary embodiment, objectslocated next to the road, for example building 42, in this case a gasstation, are either included symbolically or photorealistically in thedisplay. Explanatory comments regarding buildings 42 or otheradditionally overlaid objects are made possible by informative text 47.In one exemplary embodiment, objects recorded by camera device 10 may beincorporated in the display in display area 40. In this context, anotherexemplary embodiment provides for a perspective display, the areasurrounding the vehicle may be shown as a simplified representation, inorder to, in fact, give the driver the necessary orientation, however,without distracting him/her with a confusing display. In a mannercomparable to the superimposing of vehicle image 20 as in FIG. 2, avehicle image 43 is placed in front of the vehicle on a route 44 anddisplayed in display area 40 on road 41. In the present case, route 44turns into a side road 45 that branches off to the left from road 41presently traveled on. If necessary, a warning symbol 46 alerts a driverof the need to heed oncoming traffic. In the illustrated exemplaryembodiment shown here, on the one hand, a turn-signal area 48 forindicating a left turn, a directional arrow 49 made visible in vehicleimage 43, as well as brake-light fields 50 are activated on vehicleimage 43, indicating the need to decelerate before turning into sideroad 45. Another exemplary embodiment also provides for displaying thevehicle surroundings as a bird's eye view, in a direct plan view similarto a map display, and to enter the vehicle, as well as the guide objectpositioned in front of the vehicle, into the plan view, into the streetscenery. The driver is then able to orient himself/herself similarly towhen using a map, the guide object demonstrating to him/her the drivingmaneuvers to be performed out by the driver. Such a plan-view displaymay correspond, for example, to a representation of the vehicle andguide object in accordance with FIGS. 4 and 5 which are utilized in thefollowing to provide a general explanation of the operating principle ofthe navigational device according to the present invention.

A turning operation performed by the navigational device according tothe present invention is shown in FIG. 4. It is intended for a vehicle60, which moves along arrow direction 61, along a route 62, previouslycalculated by the navigational device and drawn in with dotted lines, ona road 63, to turn off into an exit 64. In this connection, momentaryvehicle position 65 is illustrated as a dot, which is drawn in furtheron, along route 62 at various, subsequent points in time. At a firstpoint in time, in which the dot is denoted by 65, a guide object 66 inaccordance with FIG. 2 or 3 is shown to a driver. In this context, theguide object is shown in display 3 in such a manner that the driverperceives it to be at an average distance of, for example, 50 meters infront of the driver. At a second point in time, in which the currentvehicle position is denoted by 65′, a directional signal 67 of guideobject 66 is activated, which is also shown here at approximately 50meters in front of vehicle position 65′. At a third point in time, at acurrent vehicle position 65″, the vehicle is already turned into thedeceleration lane of exit 64. Brake lights 68 are now activated on guideobject 66, indicating to the driver the need to decelerate his/hervehicle. Meanwhile, at a third vehicle position 65′″, the distancebetween current vehicle position 65′″ and guide object 65 displayed upahead has decreased, since the speed of the vehicle has also decreased.The vehicle is now guided by the guide object, in the direction of thearrow, along exit 64.

A second exemplary embodiment of a vehicle guidance using thenavigational device according to the present invention is illustrated inFIG. 5. In this instance, a vehicle 70 traveling along a road 71,encounters a vehicle driving very slowly ahead of it, for example a farmvehicle, moving at a slow vehicle velocity in arrow direction 73 alongroad 71. A precalculated route runs along road 71. An actual travel pathalong a planned route 75 is drawn in the representation as a dotted lineon road 71. At a first point in time, vehicle position 71′ is arrangedon road 71 and is guided by a guide object 74 driving ahead of it alonga route 75 drawn in as a dotted line. At a later point in time, at asecond vehicle position 71″, the distance sensors of the vehicle, e.g.,a long-range radar sensor, detect that, from the perspective of currentposition 71″, slow-moving vehicle 72 is arranged in front of thevehicle. To notify the driver of the need to decelerate, display fields76 assigned to guide object 74 are activated in the display to representa braking procedure. Other warning symbols may also be optionallyindicated. At this point, processing unit 4 checks the feasibility ofpassing slowly traveling vehicle 72. As slowly traveling vehicle 72 isapproached, sensors mounted laterally on the vehicle check whether aleft lane 77, which is separated from a right lane 78 by a lane marking79, is clear. In addition, long-range sensors check whether the oncomingtraffic in the left lane may allow a passing operation. Ultimately, thedecision is the driver's as to whether he/she would like to pass slowlytraveling vehicle 72. If he/she prepares to pass, by preparing toundertake the passing maneuver and by actuating left turn signal 80,guide object 74 indicates to him/her that the navigational device doesnot object to the passing operation. For that reason, at a third pointin time 71′″, the guide object is shown in the left lane next to vehicle72. If, on the other hand, the navigational device has reservationsabout a passing maneuver, then a warning to this effect is output to thedriver. At a fourth point in time 71″″, guide object 74 is returned toright lane 78. In this case, a right vehicle turn signal 81 is shown inoperation. The vehicle now continues to follow the previously calculatedtravel route along road 71.

What is claimed is:
 1. A navigational device for guiding a vehiclewithin a network of traffic routes, comprising: a processing unit forcalculating a travel route to a destination; a display for displaying aguide object, a movement of the guide object along the calculated travelroute being displayed in relation to a traffic route, whereby themovement of the guide object represents driving maneuvers to beperformed by a driver of the vehicle to reach the destination; adetermining arrangement to determine a traffic situation in front of thevehicle by sensing other vehicles in an area surrounding the guidedvehicle; and an adaptive controlling arrangement to adaptively controlthe movement of the guide object depending on the traffic situation. 2.The navigational device of claim 1, wherein the guide object includes avehicle image.
 3. The navigational device of claim 1, wherein the guideobject is displayed at a selected distance in front of a currentposition of the vehicle on the travel route in relation to the trafficroute.
 4. The navigational device of claim 1, wherein the display isconfigured to superimpose the guide object on the traffic route, withina field of view of a driver of the vehicle.
 5. The navigational deviceof claim 1, further comprising: an arrangement for representing on thedisplay an area surrounding the traffic route.
 6. The navigationaldevice of claim 1, further comprising: an arrangement for ascertaining ahighest permissible speed, wherein the ascertained highest permissiblespeed is used for determining the traffic situation.
 7. The navigationaldevice of claim 1, wherein the guide object includes a display area fordisplaying at least one of directional displays and warning displaysassociated with a driving maneuver to be performed.
 8. The navigationaldevice of claim 1, further comprising: an arrangement for acousticallyoutputting driving instructions associated with the guide object.
 9. Thenavigational device of claim 1, further comprising: an arrangement forrepresenting on the display an area surrounding the traffic route;wherein the guide object includes a vehicle image, wherein the guideobject is displayed at a selected distance in front of a currentposition of the vehicle on the travel route in relation to the trafficroute, and wherein the display is configured to superimpose the guideobject on the traffic route, within a field of view of a driver of thevehicle.
 10. The navigational device of claim 1, further comprising: anarrangement for ascertaining a highest permissible speed, wherein theascertained highest permissible speed is used for determining thetraffic situation; and an arrangement for acoustically outputtingdriving instructions associated with the guide object; wherein the guideobject includes a display area for displaying at least one ofdirectional displays and warning displays associated with a drivingmaneuver to be performed.
 11. The navigational device of claim 1,further comprising: an arrangement for representing on the display anarea surrounding the traffic route; an arrangement for ascertaining ahighest permissible speed, wherein the ascertained highest permissiblespeed is used for determining the traffic situation; and an arrangementfor acoustically outputting driving instructions associated with theguide object; wherein the guide object includes a vehicle image, whereinthe guide object is displayed at a selected distance in front of acurrent position of the vehicle on the travel route in relation to thetraffic route, wherein the display is configured to superimpose theguide object on the traffic route, within a field of view of a driver ofthe vehicle, and wherein the guide object includes a display area fordisplaying at least one of directional displays and warning displaysassociated with a driving maneuver to be performed.
 12. A navigationaldevice for guiding a vehicle within a network of traffic routes,comprising: a processing unit for calculating a travel route to adestination; a display for displaying a guide object, a movement of theguide object along the calculated travel route being displayed inrelation to a traffic route, wherein the movement of the guide objectrepresents driving maneuvers to be performed by a driver of the vehicleto reach the destination; and an actual highest permissible speedarrangement to determine an actual highest permissible speed at alocation, wherein the highest permissible speed is used to influence avelocity of the guide object so that it does not move more rapidly alongthe travel route than is allowed by the highest permissible speed at thelocation, so that the driver is deterred from exceeding the highestpermissible speed.